1. Field of the Invention
The present invention relates to a mobile machine for rehabilitating a track extending in a longitudinal direction, comprising a machine frame extending in the longitudinal direction and supported by undercarriages for mobility on the track in an operating direction, the machine frame being composed of a leading frame part with respect to the operating direction and a trailing frame part connected to the leading frame part by an articulation, at least one working unit mounted on the machine frame for adjustment relative thereto, and a reference system for controlling the position of the working unit.
This invention also relates to a method for restoring a position of a track.
2. Description of the Prior Art
A ballast cleaning machine composed of two frame parts which are articulatedly connected to one another is known from GB 2,268,021. A laser reference system serves for detecting the longitudinal inclination of the track in the region of the forward, leading frame part in order to be able to control, in accordance with said measurement, the vertical position of working units located on the trailing frame part. To that end, a laser transmitter is provided which is permanently kept in a horizontal position. Arranged on the front undercarriage of the leading frame part is a laser receiver which serves for detecting the longitudinal inclination of the leading frame part with reference to the horizontal laser reference plane. A longitudinal inclination value is computed via an algorithm and is then conveyed in a time-delayed manner to a further laser receiver, located on a clearing chain on the trailing frame part, in order to thereby be able to control the vertical position of the clearing chain.
Additionally known from GB 2,268,529 is a ballast cleaning machine in which respective longitudinal and transverse inclination meters are fastened to a leading as well as to a trailing frame part. The longitudinal inclination of the track is measured in the region of the leading frame part and stored as a target value which is passed on in a time-delayed manner for controlling the vertical position of a clearing chain. In this, the actual or existing inclination detected by the longitudinal inclination meter of the trailing frame part must be taken into account. For the purpose of controlling the vertical position of the clearing chain, a cable potentiometer is provided which is arranged between the trailing frame part and the clearing chain.